Turbine-blade lashing



June 30, 1925. 1,544,318

F. HODGKINSON TURBINE BLADE LASHING Filed Sept. 12, 1923 ffiada/rinsan WITNESSES: no I, ENTQR Patented June 30, '1925.

,jumr-Eo S TE? r'nano s nonexinsoiv, or" svfaa'rntionn, r'nn tsftnvnnih, Assienb'a, 'ro Whs'riiifd HOUSE ELECTRIC AND MANUFACTURING GGMPANY, A oonro-nai'r'ibn'ior rhiviv- TURBINE-BLADE tin-shine.

To all whom'z'tm'ay concern:

Be'it known that I, FRANCIS HonoKINsoN, a'subject of the King of Great Britain, and a resident of Swarthmore, in the county of Delaware and State-of Pennsylvania, have invented a new and useful Improvement in Turbine-Blade Lashing, of which the following is 'a specification;

My invention relates toturbine blading of the type having intermediate partition or wall 'eleinentsand it has for an object to provide lashing for blading of this character which shall servethepurposes of strengthening the blade structure and of minimizing blade vibration.

Another object of my invention isto provide lashing for the .1 character of blading' indicated which-is effective both to strengthen the blade structure and ,to form a packing means between the inner and outer tiers of adjacentrowsoi' moving and stationary blades. V

luyv improved lashingis particularly applicable to turbine blading ofthe multipleexhaust type, such asshown, described and claimed in thepatent to- Baumann, reissued April26, 1921, No. 15,092, andassigned to the Westinghouse Electric and Manufacturing'Company: I provide the partition or wall elements of b'lading .ofthis type with lateral grooves toreceive lashing members for-the purposes'aforesaid. H

As is well-known'in} the art, in applying blade lashing, a suitable number of blades in a row are grouped together and e lashed, leaving a joint between such grouping or segment and the adjacent group or-segment to allow for expansion due to the' different rate of heating of the rotor and the blading ofthe turbine..- In applying myT improved lashing I group a certain number of blades in themanner'aforesaid', the number depend ing on their length. I make the lashing strip, say, one and one-half times the length of a blade. Different groupings would be made, however, according to the blade design.

Apparatus made in accordance with my invention is illustrated in the accompanying drawings, forming a part of this application, in which Fig. 1 is a detail view of multiple exhaust blades with my improved lashing means applied thereto; Fig. 2 is a sectional view taken along the line 11-11 of Fig. 1; Fig-. 3- is a sectional detail View showing a modified typeot lashing. forzbladingot this character; Fig; 4: is a sectional detail view alongthe line- IVIV of F ig.-11, showing my improved lashing c'onstruction applied .to the blading shroud elements; Fig. 5 is'a sectional View showing a'mo dified form ofmy improved lashingand Fig. 6- is a sectional view showing a further modified forinwherein the lashing forms a labyrinth packing to preventleakage between the inner and outertiersofblading.

Referring now to theldrawingfora better 7 understanding of my'lnvention, i, show 111 J F ig. 1 a rotor 10 towhich'blades 11 of the multiple-exhaust type are secured by any suitable root co'n11ection,12. i v

In the drawing the blades 11 areshown provided with inner portions13 and .with

Outer portions 1-4:, separated by partition or wall elements l5-and' .16 carried, .respectively, at the front and atthe back of each blade. The blades are shown provided, at the tips,-,with shroud or wall elements-17 and 18 projecting, respectively, ;iorwa'rdly' and rearwardly of each blade. The partition or wall elements-15 and 16; and the shroud or. wall element'sl't'fand 18 are preferably made integral with the blades, andsuch elements areofsuch angextent that the partition or wall'element 15 engages with theelement l6oifathe adjacent bladeand the shroud or wall element 17 engages with the element 181015- the; adjacentbladeywhen the bladi'ng I is assembled, in order to form division {walls for the blading and shroudin-g therefor, as shown-in Fig.1. a

. Itmust be understood, however, that the location-of the partition or wall elements 15 and lG-Jand thejsl roud elements 17 and 18 as shown in. the-drawings, is for the purposes of illustration only. The enveloping which lashing strips are brazed, welded, or

soldered. In Fig. 2, I show a groove 20 at one side to receive a lashing strip 21, which is secured 1n the groove in the manner,re-,.

ferred to. In Fig. 8, I show partition or wall elements'having grooves 20 at each side Y which is strong and in order tominimize vibration thereof. V I

For ease-of insertion, my-i-mproved lashing may be formed in any desired shape. For instance, in Fig. 5 I show a strip 22 triangular. in cross-section fitting into a similar shaped recess in the partition or shroud element of the blade.

" In Fig 6 I show a moving blade 11 Se-1 cured tothe rotor 10 and a stationary'bl'ade secured to the stator of the turbine. The moving blade 11 is shown'with a partition or wall'25 similar in construction to those shown in Fig. '1 dividing the .blade into inner and outer tiers 13 and 14. The

stationary bladeSO is divided by thepartiftion26into inner and outer tiers 23 and .24.

In each side of the partitions 254and 26 are grooves 27 and 28 in which my improved lashing is secured in themanner already outlined. 'The'lashing strip-applied to the moving blade ll-has a base 29,- fitting into the groove 27 of'the partition '25 and a flange portion 32 ext'ending beyond the partion- 25. The'lashing applied to the stationary blade is similarin construction, having a base 31 fitting into the groove 28 of the partition 26, and a. flange portion 33 extending beyond the partition-26. The lashing applied to the moving blade is inserted in an inverted relation with respect to that applied to the stationary-blade so that the flange portions 32 and 33 overlap each other 'with only sufiicient clearance between to prevent rubbing. In the mannerindicated I form by means of my improved lashinga labyrinth packing preventing leakage of steam between the inner and outer tiers of blading. I

means between the tiers. 1

7 While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is notso limited,but is susceptible, of various other changes and modifications without departing 'from' the spiritthereof, and I desire, therefore, that only such limitations shall be'placedthereupon as are imposed by the'priorartor as .wall-forming flange elements carried-by each row of bladesdividing. it; into inner and outer t1ers,.grooves; 1n" the lateral faces of the wall forming'flange .elements and lashing strips fittinginto the .grooves,gsaid lashing strips having overlapping fiange portions forming packing means between the tiers. V 1

'2. A turbine bladelashing having a flange.

portion cooperating with the-flange portion the lashing of an adjacent row of blades to form a labyrinth packing.

In a turbine having a pluralityof rows of tiered blading, partition members between the tiers,.packing means betweenzthepartitionmembersofadjacent rows, said packing means being. effectivejo lash segmentsof a row of blading. i

4. In a turbine, the combination of a row of moving tiered blading, a-row of. station- 'ary tiered blading, partition. members between the tiers, lashing strips secu'redin grooves along the lateral faces of partition members, saidlashing stripshaving cooperating flange portions to form packing 5; In combination, a turbinewith rows of moving and of stationary blades, partition members dividing. the moving .and the sta tionary blades into tiers, lashing strips with laterally-extending flange portions secured in grooves along the sides of the partition members, the laterally extending flange port tions of the lashing'strips .of 'one row of blades overlapping similarzfiange portions of adjacent lashing strips. l

In testimony whereof, I have hereunto subscribed my name thisl0th day of Sept,

1923. Y FRANCIS HODGKINSON. 

